A rogue trader at the commodity broker MF Global played a large part in pushing up global wheat prices at the end of February, taking huge personal bets on the direction of wheat prices and losing $141.5m (£71m).

The company fired trader Evan Dooley at its Memphis office for an "awful" position taken on wheat futures on Chicago’s derivatives exchange during the early hours of February 27. Wheat futures suffered the largest swings in the market’s history that day, with prices changing by as much as 25%.

MF had to cover the losses under the rules of the Chicago Board of Trade.